For example, Japanese Patent Application Laid-Open Publication No. 2001-266231 (Patent Document 1) discloses a configuration in which a unit body is provided with a plurality of general-purpose interfaces based on RS-232C, and each of the general-purpose interfaces is connected to, for example, a DoPa module (trademark), a PHS module, a modem device, or a personal computer in order to collect the data of various settings or sales of an automatic vending machine online. Japanese Patent Application Laid-Open Publication No. 2006-184964 (Patent Document 2) discloses an automatic vending machine in which a remote controller used in maintenance, a money amount display device which displays the prices of merchandise, and buttons for selecting the merchandise are connected to a main control unit by a serial bus. Note that, in Patent Document 2, functions are enhanced by reducing the number of times of interruptions in serial communication processes.
Japanese Patent Application Laid-Open Publication No. H07-021452 (Patent Document 3) shows a control device of an automatic vending machine which realizes reduction of cost along with simplification of wiring operations and prevents the situation that a sold-out display function malfunctions. Specifically, complexity of wiring and overlapping of noise has been problematic when an alternating-current wiring for an electromagnetic solenoid and a direct-current wiring for a sold-out detection switch are independently provided in a vending mechanism; and this problem is solved by arranging the circuit configuration in the vending mechanism. Japanese Patent Application Laid-Open Publication No. H01-261948 (Patent Document 4) discloses a network system in which a network controller and a plurality of nodes are mutually connected by a hardware reset line in addition to by a serial data transmission path. By virtue of this, the plurality of nodes can be simultaneously reset by the network controller, and noise tolerance with respect to reset signals is also improved.
Recently, along with enhancement of the functions of an automatic vending machine, various modules have been getting mounted in the automatic vending machine. In this case, when the configuration in which the modules are connected to a unit main body (main control unit) in parallel is employed as disclosed in Patent Document 1, connectors and wiring become complex, and, depending on the number of the connectors, adding modules may become difficult. Therefore, as disclosed in Patent Document 2, the configuration in which the modules are connected by the serial bus is conceivable.
In the case where the serial bus is used, when a module is to be added or replaced, the module is connected to the serial bus, and, usually, address setting of the module has to be manually carried out by using a DIP switch or the like. However, in this case, human resources having a certain level of skills have to be ensured, and there is also the possibility of human error, etc. Therefore, realizing maintenance that is not dependent on manpower is desired.
On the other hand, it is known that the noise environment is bad in an automatic vending machine as described in Patent Document 3. The serial bus in the automatic vending machine has sometimes a wiring length of, for example, several tens of meters, and it is correspondingly readily affected by external noise. For example, when the module connected on the serial bus freezes or goes out of control due to the influence of noise, a reset operation can be tried with respect to the module by command input on the serial bus. However, the reset operation by the serial bus becomes difficult in the situation in which, for example, a certain module goes out of control and the module exclusively continues output to the serial bus.
In recent automatic vending machines, for example, the importance of a multimedia display function that draws the attention of customers and increases the purchasing chances has increased, and a large amount of data processing such as contents processing in a main control unit of the automatic vending machine and high-speed data transfer between a contents display unit which displays contents and the main control unit is needed. When the speed of data transfer is increased, the influence of above-described noise is also increased correspondingly. Therefore, ensuring reliability such as fail safe has become more and more important. Furthermore, the various modules which carry out such high-speed data transfer are expected to be increased in the future; and, not to mention ensuring above-described reliability, in consideration of addition of such various modules, the maintenance performance thereof has to be sufficiently taken into consideration.
FIG. 16 is a block diagram showing a configuration example of an automatic vending machine which has been studied by the inventors and is based on a combination of the techniques of Patent Documents 1 and 2, wherein, in the configuration, a main control unit MCTL has a port of a serial bus SB and ports of RS-232C, and various peripheral modules (functional modules) MD are connected to the ports. For example, a money identifying unit MDb, a money amount display unit MDc, a vending unit MDd, and a user input unit MDe are connected to the serial bus SB; and a contents display unit MDa and a communication unit MDf are connected to RS-232C.
The serial bus SB generally has a transfer speed of, for example, several tens of K to several hundreds of K (bps), and the plurality of peripheral modules MD are connected thereto; therefore, the effective processing speed of each of the peripheral modules MD is further slower than the transfer speed. Therefore, since connecting the contents display unit MDa or the like that requires a high processing speed to such SB is difficult, as a countermeasure therefor, separately connecting it to RS-232C is conceivable.
However, in such a configuration, when the peripheral modules MD that require high processing speeds are added later as described above, the number of the ports of RS-232C will be a bottleneck. Therefore, for example, increasing the transfer speed of the serial bus SB and connecting the contents display unit MDa, the communication unit MDf, or the like thereto is also conceivable. However, also in this case, as described above, the problems of reliability that accompanies the reset operation and the maintenance performance not dependent on manpower cannot be solved.